Process in the roasting, calcining, decarbonization, and desulphurization of carbonates, sulphide ores, and other materials, and apparatus therefor



. W. LANYON Y PROCESS IN THE ROASTING, CALCINING, DECARBONIZATION, ANDDESULPHURIZATIQN OF CARBONATES, SULPHIDE ORES, AND OTHER MATERIALS, ANDAPPARATUS THEREFOR Filed Oct. 51, 1921 2 Sheets-Sheet 1 Mar, 3, 1 925.1,528,155

' W. LANYON PROCESS IN THE ROASTING, CALCINING, DECARBONIZATION, ANDDESULPHURIZATION OF CARBONATES, SULPHIDE ORES, AND OTHER MATERIALS, ANDAPPARATUS THEREFOR Filed Oct. 51, 1921 2 Sheets-Sheet 2 Patented Mar. 3,1925.

UNITED STATES PATENT OFFICE.

WILIIAH LANYON, OF ST. LOUIS, MISSOURI.

PROGES IN THE BOASTING, GALCINHG, DECARBONIZATION, AND DESULPHUBIZA TI[ON OFGARBONATES, SULPHIDE ORES, AND OTHER MATERIALS, .AITD APPA- BATUSTHEREFOR.

Application filed October 31, 1921. Serial- No. 511,090.

ification containing a full,-clear, and exact description, referencebeing-had to the accompanying drawings, forming a part hereof. Myinvention relates to certain new and useful process in the roasting,calcining,

decarbonization and desulphurization of carbonates, sulphide ores andother materials, and apparatus therefor, and has forits primaryobjectthe subjection of ore or the other materialsdirectly to highlyheated air as either the sole or preponderating source of heat, to fullyand efiiciently perform the operation. My invention is especiallydesigned for the desulphurization. of ores, and particularly zincsulphide ores.

.My invention further consists of certain improvements in the apparatusin. connection with the revolving or rotary furnace hereinafter referredto, and illustrated in the drawing, Fig. 1, and used in connection withthe operation of the method or process above referred to.

In carry ng out my process it may be applied to any of the well knowntypes ofroasting furnaces now known to -the art, with more or lessadvantage in the results, but I deem it-tobe especially ap licable tothe revolving, or rotary type of urnace.

The illustrations disclose two types of furnace by means of which myprocess-may be carried out, Fig. 1 being the rotary type and Figs. 2 and3 being what is denomi nated in the art of zinc metallurgy as a multiplehearth zinc-ore roasting furnace.

Fig. 1 is a longitudinal sectionalview of a rotary type of furnace; andFigs. 2 and 3 are the multiple hearth type, in which Fig. 2 is a sectiontaken on the line 22 of Fig. 3, and Fig. 3 is taken on the line 33 ofFig. 2.

Referring to the drawings: 4 indicates the roasting d um preferably 13of the drum projects.

air heating chamber in which are locatedair coils 19, or other means ofheating the circular in cross section, which has a lining of refractorymaterial 5. The drum 4 is provided with rings 6, which rest onsupporting rollers 7, for holding the drum in the proper position.

Mounted on the drum 4 is the gear wheel I 8, meshi'ng with the pinion 9driven by a motor or other suitable source of power, 10.

-By means of this construction the drum 4 ma be rotated as desired. Thedrum 4 is provlded with a plurality of "openings 11 for drawing outsamples of the ore at any desired intervals of iLImGOI place, also forthe purpose of taking the temperature within the furnace, also for theintroduction of air at any desired temperature, and measuring the drum.-4

In the illustration (Fig. 1), 12 indicates the supply or receiving end,and 13 the discharg'eend, the ore or other material being-fed 'into theroasting drum by means of the hopper and conducting pipe 14. i Thesupply or receiving end 12 is provided with a beveled inwardlyprojecting shoulder v15 for preventing the material under treatment frombeing discharged from the receiving end of the furnace. This shoulderhas, another function, which will be here inafter described.

16 indicates the air heater, which may be made of any suitableconstruction, and

pressure of the gases within the may be of the continuous countercurrent type or in. duplicate or triplicate alternating hot air stovetype, and is provided with an outlet into the superheated air chamber17, into which the discharge end 18 indicates the air. As the process ormanner of heating air to a high temperature is so Well known, and is notmade a matter of claim in this invention I deem it not necessa to gointo a. detailed description of suc apparatus there being innumerablestyles and types of such furnaces in operation in metallur ical works.

he cold air, atmosphere, is fed into the I ferred to.

'lhan that temperature is required.

surrounding the air ducts. In practice in the desulphurization of ores,and to achieve my object, it is necessary to supply the heatod air tothe roasting chambers to at least-a temperature of 1150 degreesFahrenheit, and usually'and chiefly a much higher In practice the airheated to the temperature required to suit the material under treatmentin the furnace in the drum is discharged into the drum 4 from the airchamber 17 unlformly and under perfect mechanical control, preferably ataepressu're in excess of atmosphere, which pressure may be at-- tainedat will through the use of the blower 20 supplying the air, and thecurtailed outlet-created by the shoulder 15, before re- The chamber 21is designed {to receive the exit gases from material underwith the gate26 for controlling the letting its side walls with openings 31 and 32,from.

out of the burnt product and closing the chamber 17 from the outsideair.

In Figs. 2 and 3 I have shown a multiple hearth type of reverberatoryore roasting furnace used for the desulphurizing of zinc sulphide ores,which consists of the roasting furnace 27, and the hot air stove or airheating furnace 28, the two being connected together by means of, thepassage flue 29, opening into the highly heated air chamber 30. Thischamber is provided in which the heated air passes into and over thehearths or floors 33 on which the ore is resting. It will be noted inthis connection that the openings 31 are larger than the openings 32,the idea h'eingthat in practice the greater amount and-perha s all ofthe heatedair will preferably no admitted through openings 31, and theopenings 32 are provided only for use at discretion, as the characterore and heat of the furnace may require, said openings 32 being controllable toan degree'of opening. or to closing of them off entirelythrough the door openings .37. oppositeto openings 32. Above the airchamber 30 is the waste gas fiue'34. receiving the waste gases from thetop orehearths through openings 35. and onducting them thence tochimney-flue 35. In flue 35 is a damper shown as 36. for regulating theoutlet of the furnace. and passage of air andgases through the furfi'omwhich it- 'the entire furnace.

nace. This dam er may be difi'erently".l ocated or of a di erent style,any common place damper method will achieve the'oblowermost hearth andis't en removed from the furnace by raking it down through the passages38 whichlea'd to any suitable storage compartment.

In carryingoutmy proce'ss or method. particularly with relationtodesulphurizing ofores, in both types of furnace shown. or other types]commonly used i'n'the art that portion ,of the ore under treatment whichpossesses the least combustible qualities is subjected to the airmosthighly heated, direct from the air heater;

' As the air progresses through. the furnace it. comes in contact withore containing gradually increasing combustible and 'heat producingqualities, which tend'decidedly to-mainta-in the original temperatureand producea comparatively uniform and prop'-' er temperaturecontinuously throu hout- As previously re erred to, the characteristicfeature of my process is the use of 'highly heatedair, preferablysolely, but.at least in a measure to constitute the major orpreponderating heat agency, as the oxidizing agent. particularly 3 inthe desulphurizing of sulphide ores particularly zinc sulphide ores. Incase the resultant gases are to be used for the manufacture of.sulphuric acid, or other sulphurous or sulphuric uses. it isrequisitethat none of the 'oxides of carbon be present in them. Again in caseswhere the-sulphur gases are not to be utilized, but wasted. it isdesirable. if possible to exclude all fuel gases from contact with theare under treatment. as it'is well known that the carbon and hydrogen inthem under heat and contact with the metal oxides tends to burn up orvolatilize'some of the metal values. which are thereby lost to theoutside atmosphere. whereas in an atmosphere of pure :iirvolatil'ization seldom occurs. and only at such..extremelv-hightemperatures as never or selddm, and then not necessarily attained.

, Regardless of which type of furnace is employed in carrying out myprocess. the ore is subiected to an atmosphere. preferahlv of highlyheated air onlv. or an atmosphere highlv heated in which the majority orpreponderance of heat is su plied by highlv heated air. and while I t 0not deem it as obligatory. (as fair to good results may be had atatmospheric pres- I sure) I consider it as helpful and beneficial to usethe highly heated atmosphere'under pressure, in that it causes theheated air to more, thoroughly permeate the ore body and assist in itsquicker oxidation, and also as preventing any inrush of cold air fromwithout the furnace, through any door or other openings in the furnacestructure, thus preserving the heat and protecting it from beingdiminished by chilling aircurrents from without, and furthermore, inthe, rotary type of furnace I am enabled to maintain a back pressurethroughout the entire roast- ,ing chamber without the loss of anysulphur dioxide gases.

I have discovered that the rotary type, as described, of furnace isprobably the most suitable for carrying out my process, because thematerial under treatment can be kept continually and uniformly movedabout and agitated bylthe revolvin of the drum 4, and thus slowly orquick y but unceasingly presenting fresh particles of the material undertreatment to the action of the heat and the oxygen in the highly heatedair,

and at the-s ame time advancing by gravitythe material 'under treatmentfrom the feed to the discharge" end of the furnace. The advantages of myprocess may be briefly summarized as follows: The saving of fuel, owingto the making possible to a greater degree than customary theutilization of the fuel value of the sulphur contained in sulphide oresfor their own combustion; the saving of time in theoperation thusincreasing capacity of plantinstallation; a more thorough, complete andsatisfactory quality of the roast, and more easily attained; in the caseof the rotaryfurnace referred to much saving in fuel and labor over anyother style or type; supplies the maximum heat in shape of highly heatedair where most needed and a substantially uniform heat throughout theroasting furnace; in the case of the rotary furnace referred to muchless first cost of installation com ared with other types, particularlthe multlple-hearth, firc-fiue-heated-by-con uct'ion types, mostly inuse in producing sulphur gases for the' manufacture of sulphuric acid,and furthermore, the possibility of maintaining a back pressurethroughout the entire roasting chamberwithout the loss of any sulphurdioxide gases. I

It is obvious that by means of the fan blower 20, and the damper 24,that I can control the volume of highly heated air that is passedthrough the roasting drum and I can also control the pressure of thehighly heated air' within said roasting drum by increasingor decreasingthe speed of the blower. Furthermore, I can regulate the intensity ofthe highly heated air within said chamber in case of overheating bymeans of the-openings or pockets 11. This being accomplished by stoppingthe rotation of the drum while the openings are above the ore level,decreasing the speed of the fan blower, and injecting air through saidopenings or pockets. The temperature of the air may be furthercontrolled by the speed with which it is forced through the hot airfurnace by the fan blower, and the temperature of the hot air furnace Itwill be further observed that when the drum rotates, the entire mass ofore or material under treatment is always presenting a new or freshsurface for the direct action of the highly heated -air,this being inaddition to the air which penetrates (due partly to pressure. within thedrum) between .the particles of ore, and I am thus enabled to roast muchlarger particles of ore than where hand or mechanical StllllIlg. 1semployed. and the roasting is done more unlformly. thoroughly, andquickly.

other material being treated. .The other way was accomplished in whatare denominated muffle furnaces .in which the required heating medium toperform the operation is supplied by conduction and radiation of heatthrough brick walls or arches from fire fiues or chambers adjoining thechambers or spaces occupie under treatment and in some cases in addition. in these so-called muflle furnaces a smalljamount of weakly heatedair was used by introducing it into the ore chambers. But 'in all suchcases this weakly heated air was negligible as to the matter ofsupplying the requisite quantity and temperature of air and heat-suchfurnaces being dependent "practically entirely on the fire fluesreferred ployed, all of them show the use of fire gases introduced in,the ore chamber or fire flues surrounding the ore chamber and for thesole purpose of apply ng the required heat medium for the operation.

According to my im rovement in the method of roasting andesulphurization, of

by the ore ores and like material, I eliminate and make unnecessary themuffle fines or other awkward and expensive ways of supplying therequired heating medium and also eliminate the admission of fire gasesin the same chamber with the ore gases.

Having fully described my invention, what I claim is:

1. The, process of treating ores and the like, which consists insubjecting them in a furnace to the direct action of highly heated airregulated as to volume and intensity of temperature as the sole heatingagent supplied and at the same time constantly exposing a fresh surfaceto said air.

2. The process of treating ores and the like. which consists insubjecting them in a furnace to the direct action of highly heated airregulated as to volume, temperature, and pressure as the sole heatingagent supplied and at the same time constantly exposing a fresh surfaceto said air.

3. Theprocess of treating ores and the like in a furnace which consistsin subjecting the ore mass while under a continuous stream-like movementhaving a constantly .changing surface directly to highly heated airregulated as to volume. intensity of temperature and pressure as thesole heating agent supplied.

4. The process of desulphurizing ores and the like in a furnace, whichconsists in subjecting the material while the mass thereof is in motionto highly heated air regulated as to initial temperature, volume, andpressure as the sole initial heating, and ignition agent supplied. thematerial having the least.

combustible value being subjected to the air having the highesttemperature, the temperature of the air and gases in the furnace beingthus maintained substantially uniform by the increasing combustibilityof the moving mass of material under, treatment.

5. In a desulphurizing furnace for ores, a rotating roasting chamberprovided with a restricted inlet and a refractory lining, means forfeeding a stream of ore into the restricted end of the chamber. radiallyarranged pockets carried by the chamber and provided with closures, saidpockets adapted to receive a portion of the ore for sampling purposes.means for feeding highlv heated air and regulating the volume thereofinto the discharge end of the chamber, and means for regulating thepressure of the highly heated air within the roasting chamber. v j

6. In a furnace for the desulphurization of ores and the like. anunobstructed rotating drum lined with a refractory material having atapered restricted receiving and a discharge end, a chamber adjacent toand communicating with the discharge end for producing and supplying tosaid drum a 7. In a furnace for the desulphurization of ores and thelike, an unobstructed inclined rotating drum lined with a refractoryma-' terial having a receiving, and a discharge end. a chamberadjacent'to and communicating with the discharge end for receiving andsupplying a heating agent composed of highly, heated air of asufficient-volume and intensity of heat to produce and maintaincombustion of the combustible in the ore in the drum as the sole heatingagent supplied in the operation, means for supplying highly heated airfree from firing gases to said chamber, a chamber for receiving andpassing alongthe waste gases connected to and communicating with the orefeeding or receiving end, and means for regulating the escape of wastegases, whereby the pressure of the highly heated air within the drum isregulated. a

8. The process of treating ores and the like, which consists insubjecting them in a furnace while the mass is under continuous movementto the direct action of highly heated air of sufficient pressure topermeate the mass, as the sole ignition agent.

9. The process of treating ores and the like as a continuous operation,which consists in feeding the ore in stream like formation into aregulated blast of highly heated air of suflicient intensity of heat toproduce ignition, and of sufficient volume to maintain combustion, andof sufiicient'pressure to permeate the ore under treatment.

10. The process of desulphurizing a mass of ore as a continuousoperation, which consists in imparting to the mass a continuous movementand subjecting it during such movement to a blast of highly heated airof suflicient intensity of heat and volume to produce ignition andmaintain combustion,

and of sufficient pressure to permeate the mass being treated, whereby auniform and thorough roast is quickly obtained.

11. The process of desulphurizing a mass of ore as a continuousoperation, which con sists in imparting to the mass a continuousstream-like movement having an ever changing surface and subjecting itduring said movement to a supply of highly heated air of suflicientintensity of heat to produce ignition and volume to maintain combustion.

12. In a furnace, a rotating roasting chamber provided with radiallyextending and closure means for i said pockets spaced apart from theexterior surface of the shamber.

13. In a furnace, a rotating roastin chamber provided 'with radiallyarrange y pockets fonthe purpose of taking out samples of the materialsunder treatment therein, for takin the temperature thereof, andinjecting suc air supplies that might be desirable, and means foropening and closing said pockets.

14.111 a rotating reverberatory furnace,

comprising an unobstructed rotating drum, lined with refractorymaterial, having a receiving and discharge end, a hot air furnace, achamber adjacent to andcommunicatin said urn ace, for receiving andsupplying to said drum a heating agent composed of highly heated air, ofsufficient volumeand intensity of heat to produce and maintaincombustion of the combustible in the ore in the drum, as the soleheating .agent supplied for the operation, a chamber for receiving andpassing along of the waste gases connected to and communicating with theore feeding or receiving end, a hopper and pipe connection leading intothe receiving end of the drum, said drum having a plurality oflongitudinally spaced apart radial pockets formed in or on itsperiphery, said pockets being for the purpose of takmg samples of ore atvarious oints throughout the length of the drum, a so for taking thetemperature within the drum, and for the introduction of air when andwhere required, means 4 pockets, and a valve controlled means for theroasted product located in the hot air receiving chamber for receivingand discharging the roasted product. 15. The process of desulphurizing amass of ore as a continuous operation, which consists in imparting tothe mass a continuous movement and subjecting it during said movement toa blast of highly heated air under pressure of sufficient intensity ofheat and volume to produce ignition and'maim' tain combustion.

16. The method of dcsulphurizing ores which consists in crushing the oreto the desired size; taking a mass of the crushed ore and imparting toit a continuous streamlike and sliding movement so as to produce andpresent continuously and iusuccessien new surfaces on the mass of ore,and directly and simultaneously subjecting said surfaces to the actionof an atmosphere composed of therein, for tak with the discharge endconnected tofor opening and closing said highly heated air, or apreponderance there operation.

17. The process of treating ores in a furnace which consists inpermeating a portion of the mass of ore with highly heated air as thesole ignition agent while the mass is under continuous movement.

18. The process of'treating ores in a furmice which consists inpermeating a portion of the mass while under constant movement with airof sufiicient intensity of temperature to cause ignition and sufficientvolume to sustain combustion. v

'19. The process of treating ores which consists in supplying to arotary furnace a constant supply of sulphide ore causing said ore totravel through said furnace in a stream-like manner having a constantlychanging surface, and causin to pass through said furnace while sai oreis in constant movement, a stream of air of sufficient intensity oftemperature to'cause ig- 1 constant supply of sulphide or other ore,

causing said ore to travel through said furmice in a stream-like mannerhaving a constantly changing surface, and causing to pass through saidfurnace in a direction opposite to the travel of said ore while said oreis in constant movement, a stream'ofair of suflicient intensity oftemperature to cause ignition of the combustible in the ore and ofsuflicient volume to support combustion.

21. The process of treating ores and the like which consists insubjecting them in a furnace while, the mass is under continuousmovement. to the direct action of a mobile supply of highly heated airas the sole ignition agent supplied and of sufiicientment suflicient toproduce a constantly changing mass surface and simultaneously impartingto the 'ore particles a movement sufficient to present the entiresurface of said particlesto said air, and simultaneously imparting tothe volume of highly heated air a movement in a direction oppositeto themovement of the ore mass.

In testimony whereof, I have signed my name to this specification.

WILLIAM LANYO'N.

